For an air-conditioning apparatus as an example of a refrigeration cycle apparatus, studies have hitherto been conducted to improve air-sending performance of an outdoor unit being a heat source unit. As one of the air-conditioning apparatuses described above, for example, an air-conditioning apparatus disclosed in Patent Literature 1 is known, Patent Literature 1 discloses an outdoor unit including a fan, a heat exchanger, and a partition plate. The heat exchanger is arranged behind the fan. The partition plate is arranged in front of the fan, and is configured to separate a part closer to an air inlet and a part closer to an air outlet. The partition plate has a first orifice having a substantially cylindrical shape and a second orifice having a conical shape. The first orifice is formed so as to surround an outer periphery of a rear end portion of the fan and project to the air inlet, and has a distal end portion formed as an open end toward the air outlet. The second orifice is concentric with the first orifice to expand toward the air outlet, and is provided so as to continue to an outer side of the first orifice.
According to the configuration disclosed in Patent Literature 1, the following effects can be obtained. Specifically, when the second orifice is formed in a slope of a conical shape, or two levels of slopes of a conical shape are formed in the second orifice, release from the second orifice can be prevented for a large air volume. Further, when a portion of the slope of a conical shape has a flat surface facing the first orifice, flow of air can be smoothed to increase an air volume and reduce noise.